Scorpion BmK venom induces nociceptive response of rats by plantar injection.

In this study, the nociceptive responses induced by subcutaneous injection of scorpion BmK venom into the plantar surface of rat hind paw were quantified. The suitable dose of the venom is between 0.01 and 0.05 mg. The venom injection could induce local edema and tonic-pain responses, which had lasted more than 1 h. The pain scores reached peak intensity within 20 min, and then decreased slowly. Morphine, as a classic analgesic drug, could inhibit the spontaneous nociceptive response induced by the venom. With Morphine pretreatment, the mean pain scores for the entire 60 min were significantly decreased (P<.05). BmK I, a main lethal component, was also found to induce nociceptive responses with dose-dependent means. The nociceptive responses induced by BmK I could be partially inhibited by morphine.